Method of coating paper and product thereof



such as otherwise tends to occur. o of any theories in attempt to explain the results- Patented Nov. 25, 1941 UNITED STATES PATENT OFFICE-y. i lun'rnon or cos'rfs r li m I Glenn, Aurora, 111., aasignor Glenn. Davidson No Drawing. Application August 25, ms,

serial 'No. 220,705

orthosilicate, sodium metasilicate, sodium bov v 11 In coating papers such as are employed for printing usages, etc. it has been customary to prepare the paper by a simple coating of casein.

and clay. Casein while having certain advantages, is under the. disadvantage of tending to material is weaker than the casein-coated product, and its applicability has been thereby under a serious disadvantage, notwithstanding other attractive features, such as uniformity of material,

low cost, etc. I have now found however that oilseed proteinous material, that is oilseed flour or. isolated protein, or in fact such material as related ends, the invention, .then, comprises the features hereinafter fully described, and particulariy pointed out in the claims, the following description setting forth in detail certain illustrative embodiments of the invention, these being indircative however, of' but a few of the various ways in which the principle of the invention may be employed. I l The paper to be coatedma'y be any usual or preferred grade, and in accordance with my invention I apply to this, as apre-treatment or sizing, a defloccul'ating and a binder material.

Preferably, the deflocculating material is an alkaline material or agent. This prequently-applied' mineral-containing coating material which forms the finishing surfacing. There is reason .for believing that the deflocculating agent determincsa particularly uniform distributionof the mineral particles as appliedin the finish-coating, or at least prevents asgrelation Irrespective strength and firmness of the coated product. The

binder material involved as sizing agent maybe "with particular advantage tapioca, and in some casesother starch, etc; The alkaline agent may. be sodium carbonate, caustic soda, sodium alumi-- nate, trisodium phosphate, sodium pyrophosrate, amines, as ethylene diamine, morpholine, triethanol amine. etc. As an illustrative example; Two pounds of anhydrous sodium carbonate are added to a solution of four pounds of tapioca.

in one hundred pounds of water, with stirring.

until the sodium carbonate is completely dissolved. This material is applied to the surface of the paper by any suitable coating applicator means, such as to deposit approximately four-;

tenths of a pound of tapioca and two-tenths of a pound of sodium carbonate, dry weight basis.

per side of the sheet per ream of five hundred sheets each measuring twenty-five by thirty-eight inches and weighing for instance forty-five, pounds. That is, an amount of sodium carbonatel and tapioca as indicated. to about thirty-twoi, hundred 'and fifty square feet of paper surface. a A finish coat of mineral-containing materialg preferably a suspension of clay in oilseed proteinous material is applied. If the finish coating is put on by spray or roll. type of coating device, the" tapioca coating need not be dried, but if the finish coating be applied by means of a brush type of;

coating machine it is advisable to dry the tapioca coating lest the brushing disturb it too much. The paper product 'with the tapiocarsizing and the finish coating of oilseedproteinous material and clay or like mineral filler is remarkably strong, the adhesion of the finished coat and the tion as what would be expected from the paper.

' As indicated, oilseed materiahsuch as the flour Q tment very fundamentally affects the adhesion. f the subsev V the case of tapioca, and'a'pplied in similar amount as the'tapioca, also rubber latex in five per cent. j

particularly, or the isolated protein, of soya bean, peanut, and like oilseed materials as available from the residues of oil pressing or extraction, may be thus used. As indicated also, I have foundthatas the amnity-promotingsizingv theremaybe applied other starch, such as corn starch,

which may be made up to .a five percent solution and treated with ten percent caustic sods onthebasisoi'thestarch orwithsodaash,trisodium phosphate, sodium aluminate, etc., as in solution applied in similar amount as the tapioca, also synthetic urea-formaldehyde resin or acrylic acid resin using desirably ten to fifteen per cent solutions and applying one to four pounds, dry

resin basis, per side per ream of paper, also maho an! soap emulsions using five per cent suspenlions and applied at about the same rate as'tapioca, also locustgum, gum tragacanth and the I like, in analogous strength and rate of applicaphate, alkali metal silicates'or water glass, tion aswith tapioca. I have found somewhatless desirable results as comparable with the foregoing, where using dextrine in 2040 per cent solutions, applying five to ten pounds per side per ream, or water glass at the'same rate, or gum arabic at the same rate, or barium fatty acid soaps using a five per cent suspension and applyside per ream depending upon the extent of effect wanted. The defiocculating agents used may vary from 5 %-150% of the tapioca used.

The method of preparing clay or mineral surfacing material may vary depending upon the precise character of product desired, and in the case for instance of a white coated paper for the printing trades may be for example one hundred pounds of clay per twelve pounds of soya bean flour or equivalent, the mixture being madeup into a suspension by any suitable procedure, {for instance by stirring one hundred pounds of soya bean fiour to smooth suspension in four hundred pounds of water containing two pounds of pine oil, then heating the mixture to 140-l50 F., andadding' five and one-half pounds of caustic soda dissolved in twenty-five-pounds of watens This temperature is maintained for about fifteen to twenty minutes, then sixty-five pounds 'of cold water is added and the mixture is allowed to cool if not to be used at once, or it may be added directlywhile still warm, to a clay slip prepared by dissolving two and onehalf ounces of caustic soda and 12 oz. 40; 36.

water glass in forty pounds of water containing a one pound of pine oil, and to this solution one hundred pounds of dry paper-coating clay is added and the mixture is stirred until free from lumps. To this clay slip there is then added sixty pounds of the soya mixture (corresponding approximately to twelve pounds dry soya flour) prepared as foregoing. The mixture of size and clay after being thoroughly stirred is ready to be applied as in coating.

This application is a continuation, in part and I as to common subject matter, of my application Serial No. 197,879, "filed March 24, 1938.

Other modes of applying the principle of the invention may be'employed, change being made as regards the details described, provided the features stated in any of the following-claims, or the equivalent of such, be employed.

I therefore particularly point out and distinctly claim as my invention:

the paper a solution of sodium carbonate and tapioca to deposit at the rate of-two-tenths pound of sodium carbonate and four-tenths pound of tapioca, dry basis, to about thirty-two hundred and fifty square feet of paper surface, and subse quently applying thereon an aqueous oilseed flour and clay suspension containing about twelve pounds of oilseed flour per each one hundred pounds of clay.

2. In a process of coating paper, applying to the paper a solution of sodium carbonate and tapioca todeposit at the rate of two-tenths pound of sodium carbonate and four-tenths pound of tapioca, dry basis, to about thirty-two hundred and fifty square feet of paper surface, and subsequently applying thereon an aqueous oilseed flour and clay suspension.

3. In a process of coating paper, applying to the paper an alkaline agent and tapioca to deposit at the rate of two-tenths pound of tapioca, dry basis, to about sixty-five hundred square feet of paper surface, and subsequently applying thereon an aqueous oilseed flour and clay suspension.

4. In a process of coating paper, applying to the paper an alkaline agent and starch, and subsequently applying thereon an aqueous oilseed flour and mineral suspension.

5. In a process of coating paper, applying to the paper a deflocculating agent for paper-coating pigment and starch, and subsequently applying thereon an aqueous oilseed flour and mineral suspension.

6. As a new article of manufacture, paper having sodium carbonate and tapioca on the cellulose, and a superposed finish-surfacing of clay and oilseed proteinous medium.

7. As a new article of manufacture, paper having tapioca and alkaline material on the 1. In a process of coating papenapplying to cellulose, and a finish-surfacing of clay and oilseed proteinous medium.

8. In a process of coating paper, surfacing the paper with analkaline adhesive sizing, and subsequently applying to such surface a mineral suspension in oil seed proteinous material.

9. As a new article of manufacture, paper having a sizing of alkaline tapioca and a superposed finish-coating thereon of a mineral suspension in oilseed proteinous material.

10. As a new article of manufacture, paper having a sizing of alkaline starch and a superposed finish-coating thereon of a mineral suspension in oilseed proteinous material.

1 1. As a new article of manufacture, paper having a sizing of an alkaline adhesive sizing and a superposed finish-coating thereon of a mineral suspension in oilseed proteinous material.

WILIIIAM M. GLENN. 

